Relationship between urban sprawl and physical activity, obesity, and morbidity.

PURPOSE To determine the relationship between urban sprawl, health, and health-related behaviors. DESIGN Cross-sectional analysis using hierarchical modeling to relate characteristics of individuals and places to levels of physical activity, obesity, body mass index (BMI), hypertension, diabetes, and coronary heart disease. SETTING U.S. counties (448) and metropolitan areas (83). SUBJECTS Adults (n = 206,992) from pooled 1998, 1999, and 2000 Behavioral Risk Factor Surveillance System (BRFSS). MEASURES Sprawl indices, derived with principal components analysis from census and other data, served as independent variables. Self-reported behavior and health status from BRFSS served as dependent variables. RESULTS After controlling for demographic and behavioral covariates, the county sprawl index had small but significant associations with minutes walked (p = .004), obesity (p < .001), BMI (p = .005), and hypertension (p = .018). Residents of sprawling counties were likely to walk less during leisure time, weigh more, and have greater prevalence of hypertension than residents of compact counties. At the metropolitan level, sprawl was similarly associated with minutes walked (p = .04) but not with the other variables. CONCLUSION This ecologic study reveals that urban form could be significantly associated with some forms of physical activity and some health outcomes. More research is needed to refine measures of urban form, improve measures of physical activity, and control for other individual and environmental influences on physical activity, obesity, and related health outcomes.